The proliferation of capabilities and services provided through communication devices by newer systems combine a variety of short range and long range communication capabilities over a number of networks including traditional phone networks, wireless networks, and similar ones. Telecommunication end devices as well as support devices and programs for such newer systems are more similar to computer networks than conventional telephone networks. Thus, a large number of capabilities may be added to those already provided by modern telecommunication devices and networks. For example, instant messaging, voice/video communications, and other forms of communication remote desktop or application sharing may be facilitated.
Signaling and session establishment in modern communication systems such as Unified Communication (UC) systems may be accomplished employing the Session Initiation Protocol (SIP). Remote Desktop Protocol (RDP) is a protocol that can be used for application and desktop sharing. The RDP packets are exchanged by tunneling through the Real-time Transport Protocol (RTP) protocol. Communication through these protocols may encounter problems when crossing network boundaries such as Network Address Translators (NATs) or firewalls.